Behavioral disturbances occur commonly in the course of dementia. The etiology of behavioral disturbances is likely to be the result of complex interactions of biological and psychosocial factors. International comparative studies offer unique advantages in elucidating these factors by providing a wide diversity of social and environmental experiences. The Indianapolis Ibadan Dementia Project (IIDP) is a well-established longitudinal comparative population based study of dementia in African Americans from Indianapolis, IN and Yoruba in Ibadan, Nigeria. To date, the project has determined that the incidence rates for AD and dementia were significantly lower in Yoruba than in African Americans. Nevertheless, behavioral disturbances associated with dementia are a major source of distress for patients and caregivers at both sites. The purpose of this proposal is to expand the IIDP to study more intensely behavioral disturbance in demented subjects in both populations and caregiver distress by administering the Neuropsychiatric Inventory (NPI) to demented subjects and caregivers at both sites and to determine risk factors for behavioral disturbances by analyzing already existing clinical genetic and psychosocial data and to design a question to explore caregiver characteristics at both sites. The Specific Aims of the study are: 1)To compare the frequency and severity of behavioral disorder in elderly African American and elderly Yoruba subjects by administering the NPI. 2)To compare the severity of distress in caregivers of demented subjects between the two populations using the NPI. 3)To identify risk factors associated with behavioral dysfunction of AD and caregiver distress using the clinical, neuropsychological genetic and psychosocial data already collected as part of the II study. 4)To design a questionnaire to explore in more depth caregiver characteristics at both sites. For this purpose items from existing questionnaires will be used and subject to the process of harmonization and pilot testing. The data gathered from this pilot study will be used to design a more comprehensive proposal to evaluate risk factors for behavioral disturbance in dementia, caregiver response in two populations and to design possible interventions.